80 



posterior tooth of the right valve the shorter, 

 notched ; muscular impressions round. 



Syn. Cultellus cultellatus, S. V. Wood in Ann. and 

 Mag. Nat. Hist. v. vi.245. 



A VERY fragile and rare shell, differing in its oval shape as 

 well as in the form of the hinge-teeth from C. qffinis, from 

 Solen tenuis ofPhilippi and Nyst, and Solenfragilis of La- 

 marck, to any one of which it might possibly be referred. 



We are indebted to S. V. Wood, Esq., for the use of 

 the specimens figured. The species occurs in coralline 

 Crag of Sutton and the red Crag of Walton Naze. 



CULTELLUS affinis. 



Spec. Char. Transversely elongated with round- 

 ed extremities, compressed, shining, obscurely 

 radiated, upper and basal edges nearly straight 

 and parallel, the anterior margin slightly re- 

 flected and thickened within. Width three 

 times the length. Posterior hinge-tooth in 

 the right valve the larger and flattened. 



Syn. Solen affinis. Min. Con. t. 3. 



1 HE larger figures upon this plate are from fine specimens 

 discovered in the Barton Cliff by Mr. F. E. Edwards ; in 

 them the edges are so much more parallel than in the 

 Highgate (young?) shells, that they have been thought a di- 

 stinct species, and have received the manuscript name of 

 Bartone7isis ; however, the lines of growth near the beaks 

 show that the young shell was more elliptical, and there- 

 fore I must suppose them to be all one species. Small in- 

 dividuals have been found at Bognor. The teeth of the 

 hinge distinguish it from Cultellus cultellatus. 



